It is often difficult for personnel working in loud environments, or in large spaces such as warehouses or factories, to hear a standard ring of a telephone. Providing an enhanced ring signal in the form of a louder audible signal and/or a visual signal increases the likelihood that someone will become aware of the telephone call, or of the presence of a voice mail message, and respond accordingly. Numerous solutions to this problem have been proposed. However, many of these solutions require that the device be connected to the telephone system, raising possible concerns about equipment warranties and/or restrictions on equipment connected to telephone lines.
One example of a presently available device is disclosed in KR 10077798581, describing a phone holder for use with a vacuum cleaner. An optical sensor is used to measure light, with this measurement being used in connection with an illumination source that is illuminated when the phone rings. A noise generator is also provided, as well as a means of shutting off the motor of the cleaner when a call comes in.
CN 1977175 discloses a device for informing a mobile telephone user of calls and text messages when the user is far from a cellular transmission terminal. The device includes a microwave field detector, a loud sound signal generator, a bright oriented light signal generator, a communications unit, and an external warning signal generator. The device is placed about 40 cm. from the mobile telephone, and detects the microwave signal between the tower and the cell phone. Once the signal is detected, the user is alerted to the presence of a telephone call or SMS message.
US 2007/0037605 discloses a system for controlling the magnitude or timing of the alert signal generated to notify the user of a portable telephone of an incoming phone call. The alert may be modified depending on the absolute location of the phone, the relative location of the phone with respect to another object, the level of ambient light or sound, the time of day, the movement of the telephone, and/or whether the phone is being held by the user.
CN 20198599 discloses a mobile phone capable of automatically adjusting ring volume and brightness. The mobile phone measures ambient sound, and adjusts volume accordingly. The talk volume and vibration are also adjusted similarly. Brightness is adjusted based on a light sensor.
CN 102480817A discloses a light switch device controlled via telephone. The device includes a control circuit and a triggering circuit. The control circuit includes four diodes forming a rectifier bridge, a two-way diode, a current limiting resistor, and a photoelectric coupler. The triggering circuit includes an and gate, a not gate, as well as a resistor and capacitor for delaying time. A light dependent resistor is used in connection with another resistor for monitoring day and night. The two inputs of the rectifier bridge are connected to the telephone line. The voltage required to bypass the bidirectional diode is set to be the voltage that occurs when the telephone rings. The bidirectional diode is connected to the output of the rectifier. The output of the two-way diode is connected through a resistor to the anode and of the LED for the photo coupler. The negative output terminal of the LED is connected to the negative output of the rectifier bridge. The phototransistor of the photoelectric coupler has a collector connected to a power supply, and emitter that is connected to one input of a nand gate, with the other input being from the light sensitive resistor. The circuit is designed so that the light will light if the telephone is rung, and it is nighttime.
CN 103002143B discloses a control method for incoming calls and short messages for a mobile phone. An acceleration sensor on the mobile phone is commenced when the phone receives a short message or telephone call. If the acceleration value is larger than an acceleration threshold value, and infrared emitting device (separate from the phone) is actuated, and directed towards and infrared receiving device arranged beside the mobile phone. If the light intensity received by the infrared light receiving device is above a certain threshold, vibration and sound volume of the indicator are increased, otherwise, the vibration and sound volume are decreased.
U.S. Pat. No. 6,122,366 discloses a telephone with an environmentally influenced call indicator. The telephone includes a photo sensor that measures a level of ambient light. If the ambient light is above a predetermined threshold, the phone will ring in response to incoming calls. If the ambient light is below the threshold, then the telephone will not ring in response to a ringing signal. Alternatively, the sensor can output a signal with a pulse density that varies according to ambient light, with multiple thresholds being set, and different pulse densities corresponding to different intervals between thresholds. A low level ring can thus be produced for periods of low ambient light. As another alternative, a sound sensor can also be incorporated. The phone can be set up to avoid ringing in a dark, quiet environments, but to ring if either the ambient light or sound level is loud.
The Aaroncake website discloses a ringing phone light flasher. The device connects to the telephone line, and current will flow through the connection to the phone line when the voltage exceeds that of the 20 V Zener diodes. Current flowing through this connection will activate an opto-isolator, and will then use a transistor to activate a relay to supply power to the lights.
Algo provides a telephone ring indicator that can adjust the volume of the audible ring signal based on noise within its environment, and can provide a visual LED strobe signal for quiet locations. The device must be connected to a Power over Ethernet network switch.
The CyberData SIP Office Ringer connects to a Power over Ethernet switch, and provides an audible ring indicator.
The Viking SR-IP Loud Ringer provides an audible ring indication, adjusting the volume to compensate for background noise, and also provides a visual ring indication. It is connected to a local area network.
Many of the above devices require an electrical connection to the telephone and/or telephone system in order to function, thus potentially raising concerns about device warranties, and restrictions on equipment connected to telephone lines. Accordingly, there is a need for a device that can provide a ring indication without an electrical connection to the telephone or telephone system, avoiding any warranty issues, avoiding connection to the telephone line and associated restrictions, and simplifying installation. There is a further need to detect an incoming call and/or the presence of a message utilizing signals provided externally to the telephone, and to distinguish between an incoming call and a message.